“However for years that’s meant buying pints that have done an extra 200-plus miles just because someone has closed the local dairy, and moved it to central England.”

Proper Welsh was conceived in the wake of the demise of Dairy Farmers of Britain in 2009, when the last major bottling plant in South Wales closed.

It has taken 18 months to source finance, strike deals and find premises.

Proper Welsh milk from North Wales producers is being collected, processed and distributed at South Caernarfon Creameries, near Pwllheli.

The company aims for further roll-outs in South Wales in early May once it has established a bottling facility in the Swansea area. A unit has been identified at Cross Hands but rental deals are still being finalised.

Some £1.4m has been raised from the banks to buy new bottling equipment, with the aim of producing Welsh cream and other products in the longer term.

“We want to be a pan-Wales dairy brand,” said a spokesman.

“By establishing a unit at one end of the M4 corridor, we can source milk from the south west milk field and quickly supply consumers in south east Wales. SCC will continue to process milk in the north."

Proper Welsh aims to make a virtue out of its origins – milk from the north and south will have different labelling. It insists Proper Welsh is a non-export product – its milk will “never set hoof across the border”.

Management is drawing up a marketing campaign that may include viral videos of cows being turned back at the Wales-England border.

Consumers will be reminded that most supermarket milk sold in North Wales has travelled 200 miles from farmgate to fridge. In South Wales, the average journey is 360 miles.

Dai Miles said: “Sadly much of the milk drunk in Wales in recent years has gone on quite a journey – much of it to Birmingham, some further away still.

“It’s crazy when you think how bulky milk is, and what a nuisance all those extra lorries are, trucking it from Welsh farms, then back to Welsh stores.

“The milk you’ve been pouring on your cornflakes lately has probably been further than your last family mini-break.”

As the leading organic milk co-operative in Wales, Calon Wen is wary of compromising its original brand with a conventional milk product.

Initially Proper Welsh will be using surplus Calon Wen organic milk, but the group aims to recruit conventional producers over the next few months.

The company is pledging to pay top-end prices to its producers, though this will result in a small retail premium compared with mainstream rivals.